title: Structural, dynamic, and chemical characterization of a novel S-glycosylated bacteriocin.
abstract: Bacteriocins are bacterial peptides with specific activity against competing species. They hold great potential as natural preservatives and for their probiotic effects. We show here nuclear magnetic resonance-based evidence that glycocin F, a 43-amino acid bacteriocin from Lactobacillus plantarum, contains two β-linked N-acetylglucosamine moieties, attached via side chain linkages to a serine via oxygen, and to a cysteine via sulfur. The latter linkage is novel and has helped to establish a new type of post-translational modification, the S-linked sugar. The peptide conformation consists primarily of two α-helices held together by a pair of nested disulfide bonds. The serine-linked sugar is positioned on a short loop sequentially connecting the two helices, while the cysteine-linked sugar presents at the end of a long disordered C-terminal tail. The differing chemical and conformational stabilities of the two N-actetylglucosamine moieties provide clues about the possible mode of action of this bacteriostatic peptide.
authors.affiliation: Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand. h.venugopal@massey.ac.nz
authors.forename: Hariprasad
authors.initials: H
authors.lastname: Venugopal
authors.forename: Patrick J B
authors.initials: PJ
authors.lastname: Edwards
authors.forename: Martin
authors.initials: M
authors.lastname: Schwalbe
authors.forename: Jolyon K
authors.initials: JK
authors.lastname: Claridge
authors.forename: David S
authors.initials: DS
authors.lastname: Libich
authors.forename: Judith
authors.initials: J
authors.lastname: Stepper
authors.forename: Trevor
authors.initials: T
authors.lastname: Loo
authors.forename: Mark L
authors.initials: ML
authors.lastname: Patchett
authors.forename: Gillian E
authors.initials: GE
authors.lastname: Norris
authors.forename: Steven M
authors.initials: SM
authors.lastname: Pascal
mesh_terms: D000117:Acetylglucosamine / Q000737:chemistry; D001430:Bacteriocins / Q000737:chemistry* / Q000378:metabolism; D003545:Cysteine / Q000737:chemistry; D004220:Disulfides / Q000737:chemistry; D006031:Glycosylation; D007700:Kinetics; D048191:Lactiplantibacillus plantarum / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008958:Models, Molecular; D010100:Oxygen / Q000737:chemistry; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D017433:Protein Structure, Secondary; D012694:Serine / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry
chemical_list: D001430:Bacteriocins; D004220:Disulfides; C557037:glycocin F, Lactobacillus plantarum; D012694:Serine; D013455:Sulfur; D003545:Cysteine; D010100:Oxygen; D000117:Acetylglucosamine